Shiite cleric Muqtada al-Sadr has ordered a six-month suspension of activities by his Mahdi Army militia in order to reorganize the force, and it will no longer attack U.S. and coalition troops, aides said Wednesday.

The aide, Sheik Hazim al-Araji, said on Iraqi state television that the goal was to "rehabilitate" the organization, which has reportedly broken into factions, some of which the U.S. maintains are trained and supplied by Iran.

"We declare the freezing of the Mahdi Army without exception in order to rehabilitate it in a way that will safeguard its ideological image within a maximum period of six months starting from the day this statement is issued," al-Araji said, reading from a statement by al-Sadr.

In Najaf, al-Sadr's spokesman said the order also means the Mahdi Army will no longer launch attacks against U.S. and other coalition forces.

"It also includes suspending the taking up of arms against occupiers as well as others," Ahmed al-Shaibani told reporters.

Asked if Mahdi militiamen would defend themselves against provocations, he replied: "We will deal with it when it happens."

The order was issued after two days of bloody clashes in the Shiite holy city of Karbala that claimed at least 52 lives. Iraqi security officials blamed Mahdi militiamen for attacking mosque guards, some of whom are linked to the rival Badr Brigade militia.